Modifying unwarranted variations in health care: shared decision making using patient decision aids.

Shared decision making is the process of interacting with patients in arriving at informed values-based choices when options have features that patients value differently. Patient decision aids (PtDAs) are evidence-based tools designed to facilitate that process. Numerous randomized trials indicate that PtDAs improve decision quality and prevent overuse of options that informed patients do not value. Therefore, they have a potential role in reducing unwarranted variations in the use of preference-sensitive health care options. However, barriers to their widespread use need to be addressed with coherent plans for ensuring good standards, improving access to PtDAs, training practitioners, testing practice models, and launching demonstration projects.